The next big deal — or debate — in the transportation field isn't a Jetsons-style flying car, high-speed train or monorail. It's the Hyperloop, a 19th-century mailroom technology with a 21st-century twist. Instead of sucking documents through a pneumatic tube from the basement mailroom up to the executive suite, SpaceX founder Elon Musk and Tesla Motors' Hyperloop would propel people, seated inside pods, from L.A. to San Francisco in 30 minutes. That's about 760 mph, the speed of a cruising F-15.

That is, if it ever is built. If it ever can be built.

"We wouldn't be wasting our time if we didn't think so," says Patricia Galloway, the first female president of the American Society of Civil Engineers, who is part of a Los Angeles–based group charged with figuring out how to make Hyperloop a reality.

Also on the "Hyperloopers" team — which is working out of the transformed former Howard Hughes Spruce Goose hangar at Playa Vista — is Paul Coleman, one of the original 100 engineers NASA hired for Apollo moon missions.

As UCLA emeritus professor of space physics, Coleman posits their chances of success this way: "I don't even know where to start with the challenges. ... One is to make this a realization and do it by getting this huge crowd of Internet folks engaged in the process, engineers and people from other disciplines from all over the world."

His practical concern is how to limit the G-forces at near-sonic speed — shaking that could make passengers lose their lunch all over their fellow travelers, not to mention the pod's walls, floors and ceilings.

That's what prototypes are for, Galloway responds. To address this problem, the Hyperloop route "has to be in a straight line," she says. "We want to ferret out the problems before it gets built. I think there's more than a better chance that this will be done."

For the next year, UCLA Architecture and Urban Design professor Craig Hodgetts and his graduate students will join forces with private and university physicists and engineers at UCLA's cross-disciplinary IDEAS facility in Playa Vista, ensconced inside the very building where Hughes built his singular, all-birch war transport plane, the Spruce Goose.

Hughes' wooden marvel, the largest aircraft of its time, turned out to be an albatross. Hughes himself co-piloted it over Long Beach Harbor for its short, and only, flight in 1947 — an irony that is not lost on Hodgetts.

But Hodgetts, who oversaw the acoustical redesign of the Hollywood Bowl, insists Musk's plan is doable.

Suspended on pylons erected in the median of the I-5 freeway, the Hyperloop tube would carry passengers in pods that look a little like narrow tank cars. "Short of figuring out real teleportation, which would of course be awesome (someone please do this), the only option for superfast travel is to build a tube over or under the ground that contains a special environment," Musk wrote in an alpha-design white paper detailing his plan.

Musk has said his project would cost one-tenth that of the increasingly unpopular California High-Speed Rail, though many have challenged his figure. Voters in 2008 approved by a thin margin Proposition 1A, which allowed $10 billion for the bullet train's first phase and total costs of $33 billion, with legal strings attached: It had to zip from L.A. to San Francisco in less than three hours.

Now it has morphed into a $68 billion plan with a sluggish design, which, the Reason Foundation has found, would take nearly four hours and would attract a fraction of the riders the state claims.

In November, a judge refused to allow the state High-Speed Rail Authority to sell bonds to pay for phase one.

Qualified outside observers are naturally cautious about Hyperloop. Top engineers at Caltech declined to comment on its feasibility, with one saying that the project crosses so many disciplines — physics, engineering, architecture, construction, safety and economics — that he felt unqualified. Ditto at Santa Monica's Rand Corporation, where spokesman Warren Robak reached out to some transportation and technology folks, but "no one seems interested in talking about it."

In the 1970s, Rand engineer Robert Salter investigated a "vactrain" of transportation tubes built underground, which employed a "vacuum or near vacuum" to whisk passengers at 4,000 mph. He concluded that the vactrain faced too many hurdles, including prohibitive costs.

Fast-forward 40 years. Hodgetts says that his team of UCLA and private designers, scientists and engineers will complete a workable design in a little more than a year — including a mock-up of both the pneumatic tube and the traveling pod.

Other members of the Hyperloopers are engineer Marco Villa, former director of mission operations at Space X; and Hitoshi Abe, chairman of UCLA Architecture and Urban Design.

Aside from engineering and physics components, Abe says, "As with all innovations of this scale, it's not the technology itself that is the most important but how cities and people change because of the technology and how these changes are reflected in the urban environment."

The public-private project's initial funding came from JumpStartFund, a crowd-powered online incubator led by Jumpstarter Inc. co-founder Dirk Ahlborn and space physicist Coleman.

"If the political and economic will were acquired," Hodgetts says, "we could start construction in 18 months. It's that close to realization of the working technology and principles."

Musk's system would consist of a low-pressure tube in which capsules are transported at both low and high speeds. The capsules, each containing numerous passengers, would be supported by a cushion of air — like pucks on an air-hockey table. A "magnetic linear accelerator" affixed at stations along the tube would power rotors on each capsule.

"There's not a single element of science fiction," Hodgetts says. "Hyperloop is the same thing as the pneumatic tube."

But on steroids.

Onboard solar arrays would power the high-efficiency system. "It coasts 30 miles between pulses," he says. "How far can your car coast, even on a hill?"

A key stumbling block is that the route must be in a straight line, or nearly so. Too much curve and the G-forces slamming riders around "would be like Tom Cruise in the movie Top Gun," Hodgetts says.

On the plus side, constructing the system on the I-5's median could reduce the private property–rights wars and environmental impacts that have turned many Californians against the bullet train.

"Costs are more up front but less on the back end," Hodgetts says. "We're like a small-scale automotive group putting together the next generation of Lamborghinis, which is something not very handily done by a large corporation. We can be very agile because there's no corporate bureaucracy telling us what to do."

Galloway insists, "This is not a we-versus-them." The California High Speed Rail Authority "can do what they think is right, and we're doing this."

In his personal life, Hodgetts opts for simpler contraptions, such as his 1974 Alfa Romeo. In high school, he dropped a Cadillac engine into a Studebaker, called it a Studellac and drag-raced "because I liked speed and I wanted to attract members of the opposite sex." His iPhone is for phone calls only — no texting.

When it comes to the Hyperloop, though, he's all about the future. Hyperloop will be transformative, he says, like the war between internal combustion engines and steam engines. Within 100 years, Hodgetts predicts, we'll see the demise of oil-based engines and a fierce battle between electric and hydrogen propulsion. He imagines self-driving cars delivering people from LAX to the San Fernando Valley. But a Jetsons car is out of the question.

"You can't stop in a flying car. So think about the collisions," Hodgetts says. "Can you stop on a dime in an aircraft? No way."

Coleman is less diplomatic. "Do you really want to be up there with idiots flying in cars they can't stop?"